winkler



7, 1943; A. H. WINKLER CARBURETOR Filed May 1s, 1941 M//N/a @421821 A i z Y 2 INVENTOR e I ITORNEY Y duced.

vPatented Sept. 7, 1943,

Bendix Aviation Corporation,

South Bend,

Ind., a corporation of Delaware4 Application May 16, 1941,'Serial No. 393,692

e 12-c1aims. This invention relates generally 'to carburetors for internal combustion engines and more particularly to throttle valve control means'for multiple stage carburetor systems. y

Multiple stage carburetor systems for internal combustion enginessuch as are commonly used in automotive vehicles or the like may comprise' either a plurality of independent carburetors or an integral carburetor having a plurality of induction passages.' In either arrangement, there` are a plurality of induction passages connected with a common intake manifold or complementary manifolds,\throttle yalves for the respective passages and means for. controlling said valves whereby the respective stages of the carburetor system are brought into operation progressively. In carburetor systems of Vthis character diniculty has been encountered in properly controlling the fuel-to-air 'ratioI of the fuel mixture during the starting and warming-up period of engine operation particularly when the temperature of the engine is low. l s

When the engine is cold, it requires a very rich mixture for starting and a somewhat leaner mixture during the warming-up period, although during said warming-up period a richer mixtureis normallyV required than when the engine is lop'- erating at its normal'temperature. vDuring said warming-up period of engine operation it is particularly desirable 'that the velocity ofthe airvin the induction passages of thecarburetor system `Vbe as great as possible in order to pick up sufiicient fuel to provideuaI suitable mixture `of combustible proportions and to maintain' the fuel in the air stream and obtain the proper degree of equal distribution of the fuel mixture to the various cylinders of the engine. f

Such desired high velocities of air will be present in the primary induction passage of the carvburetor system as long as all or substantially all of the air entering the induction`system of the engine passes throughV said'v primary induction passage. However, as it is often diilicult for the operator of the automobile to determine accurately` how far the accelerator pedal may be depressed without opening the pjlementary throttle valve, said valvemay be inadvertently opened during the starting or warming up period of n- \gine operation and a part ofthe air to the engine induction system will enterthrough the supple` mentary induction passage or passages and the velocity of said entering air will befgreatly re- The expedient of providing fa conventional choke valve ine'ach of the induction passages and 55 combustion engine controlling same by any of the usual manual or automatic means increases the cost of the carburetor system and does n'otsolve the problem of controlling the fuel-to-air ratio under the above "l tion to provide relatively inexpensive means for mentioned conditions of engine' operation and it is, therefore, an important object ofxthe invenovercoming said difficulties in controlling the fuelto-air ratio in a multiple stage carburetor system during the starting and warming-up pe- .s riod of engine operation.

Another object of the invention is to provide,-w in a multiple stage induction system, means for rendering the supplementary part of the induction ys'ys'temrinoperative when the engine is operated at subnormal temperatures.

Still another object of the invention is to provide, in a'multiple stage carburetor system having a plurality of induction passages with valves controlling the fluid flow therethrough, temperature responsive means for locking at least one of said valves in the closed position when ,the `engine is operated at subnormal temperatures.

Afurther object of the invention is to provide a device of this character wherein the locking means is responsive to engine temperature.

A A still further object of the invention is to provide a device of this character including means f to permit full opening of the primary throttle valve while the supplemental supply is rendered inoperativewhen the engine temperature is sub# normal.

In one of the types of y by the differential ofv pressures on opposite sides thereof. ls provided for the Supplementary mixture passage' or passages and it is another object of the invention to provide temperature responsive means for latching such unbalanced valves in the closed or substantially closed position when e the temperature ofthe engine 'is below normal.

'I'he characteristics and advantages ofthe inventin are further sulciently referred to in connection with the following detailed description of the accompanying drawing which represents certain preferred embodiments. After considering these exampla'es, skilled persons will understand that many v riations may be made without departing from the principles disclosed; and Iontemplate lthe employment of any structures,'ar rangements or modesJof operation that are prop- -erly within the scope ofthe appendedclaims.

In thejdrawing: v A Y L Figure 1 is a fragmentary elevational view of an provided with a mulmultipl'e stage carburetors v 'an auxiliary unbalanced throttle valve, operable tiple stage fuel induction system employing the invention; and

Figure 2 is a similar view disclosing a modified form of theinvention.

While the present invention is shown and described embodied in a multiple stage carburetor system having a. plurality of independent carburetorsv it may be embodied in an integral carburetor having a plurality of induction passages.

Further, the present invention is illustrated and described as embodied in a carburetor system of this character having one primary and, one

. auxiliary or supplemental induction passage, al-

erence character, and in the specification and' claims reference to the engine as being cold, or its temperatures as being "normal, "subnormal" or low relates to normal operating temperatures thereof.

It may also be embodied in a` Referring now .to Figurey 1, reference numeral I8 indicates an engine generally and I2 indicates the intake manifold thereof having attached thereto a primary carburetor P and a secondary or supplementary carburetor S. Both carburetors comprise an air horn section I4, a body section i6 and a throttle body sectionl and each carburetor has an induction passage including an air entrance 20, venturis (not shown) and mixture chamber 22; a fuel chamber 24, fuel nozzle 26,l

and simple idling system 28. The primary carburetor P is also provided with the usual acceleration pump and economizer system indicated at 80 and 32 respectively. However, if desired, the secondary or supplemental carburetor S may also be provided with an acceleration pump and economizer system. Said primary carburetor P is further provided with the usual unbalanced mally effect opening movement of the secondary throttle valve 56 after the primary throttle valve 54 has been opened a predetermined amount. The other end of lever 68 is connected with throttle lever 58 by means of a rod 80 which is slidably received in a collar 82 pivotally attached to the lever 58. A member 84 is secured'to rod 80 adjacent its free end and is spaced from said collar 82, said rod 8 0 having .a spring 86 thereon which reacts between the member 84 and collar 82, said spring 86 being of such character as to normally overcome the valve closing pressure of spring 59 when the throttle valve actuating mechanism is actuated in the opening direction and the lost motion between collar 14 and member 'i6 has been exhausted. The throttle valves are actuated by the usual acceleration pedal (not shown) connected with lever 66 by a rod 61.

Temperature responsive means for locking the secondary throttle valve in its closed or substantially closed position when the engine temperature is below normal comprises a lever 90, pivoted at 92 to a convenient fixed member and having a lug 94 adjacent its free end adapted to engage a linger 96 adjacent the free end of lever 58. A bimetallic thermostatic element 98 is attached at one end to a pin |00 secured in lever 90 and at the other end to a lug H02 formed integral with or attached to some convenient part of the engine to be thereby responsive to variations in engine temperature.

The operation of the above described mechanism is as follows:

When the engine is not in operation both throttle valves are normally closed and when the engine temperature is below that of normal operation the lever 90 is so positioned by the thermostatic element 98 that lug 94 is beneath finger 96 of lever 58, thereby preventing opening of throttle valve 56 vby the ithrottle valve operating mechanism and rendering the supplemental source of fuel mixture inoperative. Therefore, during cold starting and the warming-up period the engine is supplied with a fuel mixture only,

i valve 34 (or other mixture enrichment device) of choke valve 94 on a shaft 36 which may be manually or automatically operated in any known manner. The shaft 36 is provided with a lever 42 connected to a fast idle cam 44 by a rod 46, said cam being engageable with a screw 48 in one arm of a throttle lever secured to a throttle shaft 52 carrying the primary throttle valve 54. However, any other suitable fast idling mechanism may be provided. Throttle shaft 53 of the secondary carburetor carries'a throttle valve 56 and has -a lever 58 secured to one end thereof. A spring 59, attached to lever 58 isprovided to yieldingly close throttle valve 56.

Means for manually operating both throttle valves includes a bell crank pivoted at 60.' One arm 62 'of the bell crank is connected with the period of engine operation.

therefore, that locking of the throttle valve 56 the primary carburetor and the actuating mechanism therefor controlsthe richness of the mixture for starting and during the warming-up It vis apparent,

in the closed or substantially closed position makes unnecessary the use of a choke valve in the secondary carburetor and the normal functions of the fuel induction system during starting and warming-up of the engine are taken care of in the usual manner by the primary carburetor. As all of the air to the engine then passes through x the primary induction passage when the engine is operated below normal temperature, the fvelocity of said air is much greater than it would .primary throttle lever 50 by means of arod 618 and the (other ami 66 of the bell-crankhas an engage said collar upon opening movement of.

the throttle valve actuating mechanism to norbe if some of it were also admitted through the secondary induction passage. Consequently, with to set the supplementary throttle valve 56 in a Y slightly open. position to provide a suitable idling -It will be obvious mixture and this may be done without-materially reducing the velocity of air in the induction system during starting and warming-up periods of engine operation. i

When the throttle valve 56 is locked in the closed or substantially closed position, the primary throttle valve 54 may be fully opened, if the operator so desires, and said opening of valve 56 will not be prevented by' said lo'ckingof the secondary throttle valve, due to the override between rod l2 and lever 68and the yielding of moved' out of the path of finger 96, thereby permitting normal opening of throttle valve 5S by the valve actuating mechanism.

. -shown in Figure 1 or of any other suitable type.-

valves may both be actuated in the normal manner, valve 56 opening. later than valve 54.

However, the supplementary charge forming device is rendered inoperative when the engine temperature is subnormal by the thermostatic element |40 which controls lever |36 and moves same into and out of locking association with lug |32 of weight |30 according to whether the engine `is below or at normal operating temperature. vWhen the engine temperature is subnormal the primary carburetor, which is a normal carburetor fprovided with a choke valve 34, fuel pump 30,

economizer system 32, and fast idle' (not shown) provides the engine wits its fuel mixture in the r usual manner. The fast idle may be of the type It should be noted, however, that the secondary L carburetor may also beprovided with an acceleration pump, economlzer system and `choke valve,

During the cooling o-i period-of the engine,

`the throttle valve 56 is normally closed and the thermostatic element 90 moves lever 90 into a position whereat said valve 66 is 'locked against opening while the engine temperature .is subnormal.

Armodification 0i the invention is shown in Figure 2, wherein the primary throttle valve shaft 52 is provided with a lever I0, said llever having an extension H2, adjacent the free end of which is pivotally connected a rod H4, the other end of said rod being slidably received in a collar H6 pivoted to a secondary throttle lever I |8 secured if desired. Locking of valve |28 in the'closed position when the engine temperature is subnormal prevents the secondary carburetor from delivering fuel mixture even though throttle valve 56 may be opened. At normal engine tempera-` tures, with the latching mechanism disengaged, suction in the intake manifold will'operi valve 28 when throttle valve'56 -is opened. The air ilow auxiliary valve |28 is adapted to normally operate, when unlatched, in a manner` similar to the to one end of shaft 53'. A flange |20 is'secured to rod ||4 in spaced relation to the collar 4||6 "against which said flange is adapted to abut. .upon a predetermined opening movement of the valve opening mechanism and further valve opening movement of said mechanism is adapted to effect` opening of the secondary throttle valve56.

A riser |23 is interposed between the secondary carburetor. S and the intake manifold |2 and is provided with a passage |24 which forms a continuation of the induction passage of said carburetor S. The riser has a shaft |26 on which is mounted anunbalanced auxiliary throttle valve |28 operable by air flow through passage |24 and closed by. a-weight |30 attached to one end of shaft |26. However, a spring or other suitable valve closing means may be substituted for said weight |30. Weight |30 has a4 projection or lug |32 adapted to be engaged, when valve |28 is closed, by a nger |34 of a lever |36 pivoted at auxiliary air flow valves disclosed in the co-pending application of'Emil O. Wirth, for Charge forming devices, .Serial No. 357,860, i-lled September 23, 1940, and the present invention may be used in connection with multiple stage charge' forming systems such as' are disclosed in said application, or it mayk be used in connection with lcarburetor systems such as disclosed in the copending application of Winklerand Gore, for Carburetors, Serial No. 384,274, filed March 20, 1941. It may also be used in multiple stage carburetor systems wherein the 4valves controlling the fuel mixtures are controlled .by other types of manual or automatic means ,thanthose disclosed herein or in the above mentionedv applications.

While the carburetors hereinshown and described are of the downdraft type, thepresent invention may also be embodied in carburetors of any other suitable type such as, for example, the updraft or horizontal delivery type. It should also be noted that the multiple stage car'- b'uretor systems with which the present invention may be incorporated may comprise an integral 1 carburetor with a plurality of induction passages |38 and actuated by a thermostatic element |40 -having one end xed to a stud |42 integral with the intake manifold |2. The thermostatic element is -bent partially about the pivot |38 and connected to a pin |44 in lever |36. The thermostat is again positioned to respond to variations in the temperature of the engine.

It should be noted in connection with valve |28 that it may be desirable Ato permit slight opening thereof during the' starting and warming-up period of engine operation to provide for the delivery of an idling mixture by the supplementary l induction passage as well as by the pri sage. Such slight opening of said valve |28 may be provided by suitably y |34 of lever |36 when said valve is closed andthe lever |36 is inthe latching position.v y

from the foregoing descripthe throttle valve actuating mechanism throttle tion of of the embodiment of Figure 2 that the spacing lug |32 and fingerv TY pas'.

as Well as a plurality of independent carburetors as shown and described herein. j Where said sys-, tem comprises an integral carburetor, it mayhave-a common air inlet for a plurality of induction passages with a single choke valve or it may have individual air inlets which choke valves therefor. The present invention may be embodiedin any of the, foregoing arrangements and where there are a plurality of supplemental induction passages it is, preferable to provide thermostatic latching means of the present invention for each of the supplemental throttle valves therefor or the auxiliary valves thereof, although some engines may not require valve latching means for all of the supplementary passages. It

should also be noted that any other suitable'temperature responsive means may be employed to' control thesupplementary induction passage or passages.

However, it is not intended to the invention to the details'shown'or described, since said temperature responsive means for 'rendering an induction passage inoperative when the engine temperature is low.

2. In a multiple stage carburetor system for an internal combustion engine having a plurality of induction passages controlled by throttle valves, means for progressively actuating said valves, and vtemperature responsive means adapted to prevent fluid ow through an induction passage `when the engine temperature is subnormal.

3. The invention defined in claim 2, wherein.

at least one throttle valve is times.

4. In a multiple stage carburetor system for internal combustion engines, said system having fully openable at all primary and supplemental induction passages for delivering primary and supplemental fuel mixtures, throttle valves for said induction passages, means for successively actuating said valves, and means responsive to engine temperature for preventing delivery of a supplemental mixture when the engine temperature is low.

5. In a multiple stage carburetor system for internal combustion engines, a plurality of. induction passages, throttle valves controlling said passages, means for operating said valves in series, temperature responsive means for locking a throttle valve in a substantially closed position when the engine temperature is low, and means permitting at least partial opening of .another throttle valve.

6. In a multiple stage 'carburetor system for internal combustion engines, a primary and a secondary induction passage, throttle valves for said passages, means for progressively opening said valves, and means responsive to engine temperature for locking the throttle valve of the secondary passage in a substantially closed position at subnormal operating temperatures of the engine.

7. The invention dened in lclaim 6, including means for permitting substantially full opening` of the throttle valve for the primary induction passage when the secondary throttle' valve is locked in said closed position.

closed position when 8. In a multiple stage carburetor system for internal combustion engines, a primary and a secondary induction passage, a throttle valve for each passage, means for opening said valves whereby the secondary valve is opened later than the primary valve, temperature responsive means for locking the secondary valve in the closed position when the engine temperature is below normal and releasing said valve when said temperature is normal, and yielding means permitting full opening of the primary throttle valve when the secondary valve is locked. Y

9. In a multiple stage carburetor system for internal combustion engines, a plurality of induction passages and throttle 'valves therefor. means for actuating the throttle valves, an auxiliary valve in at least one of the induction passages operable by air flow through said induction passage, and temperature responsive means for locking said auxiliary valve in a substantially the l.engine temperature is below normal.

10. In a multiple stage' carburetor system for internal combustion engines, a primary induction passage, a secondary induction passage, a throttle -of which is normally closed, means for actuating' the throttle valves, and temperature responsive means for rendering an induction passage inoperative when the engine temperature is low.

l2. In an internal combustion engine having an intake passage, means forming a plurality of mixing conduits for supplyingfuel to said passage, a manually operated throttle valve forone of said conduits, and a suction operated throttle valve for the other of said conduits, said last named throttle valve being so constructed and arranged as to be solely controlled by suction and temperature.

ALBERT H. WINKLER. 

